EP0863884B1 - Process for preparing bis-alkoxy-triazinyl-amino-containing stilbene disulphonic acids or their derivatives - Google Patents

Abstract

The invention concerns a process for preparing bis-alkoxy-triazinyl-amino-containing stilbene disulphonic acids or their derivatives, characterized in that bis-chlorotriazinyl-amino-containing stilbene disulphonic acids or their derivatives are reacted with at least 10 mol equivalents of a C1-C4 monoalkanol, relative to the stilbene disulphonic acid compound.

Description

The invention relates to a process for the preparation of bis-alkoxy-triazinyl-amino-containing Stilbene disulfonic acids or their derivatives and their use as optical Brightener for organic material, especially for paper and cellulose, in particular for photo paper.

Optical brighteners based on substituted bis-triazinylamino-stilbene-2,2'-disulfonic acids, where each triazine residue in addition to the substitution by the flavonic acid and another amine is substituted with an alkoxy group, and a process for their production is known in large numbers.

The alkoxy radical is normally only present in the first or in the second stage of an acid binding agent. So you put an alkanol with cyanuric chloride or with a cyanuric chloride derivative containing two chlorine atoms around. Considerable undesirable side reactions occur due to multiple reactions on the cyanuric chloride. The introduction of an alkoxy group in the third stage, i.e. in a cyanuric chloride derivative containing only one chlorine atom requires special conditions, such as. working in anhydrous glycols or glycol monoalkyl ethers in the presence of the corresponding sodium alcoholate (DE-A 1 444 015).

JP-A 305 983 describes bis-triazinylamino-stilbene-2,2'-disulfonic acid derivatives Methanol reacted in a 1: 2 ratio or with a small excess of methanol.

DE-A-2 335 570 describes that when using glycols or glycol monoalkyl ethers it is possible to react them with bis-triazinylamino-stilbene-2,2'-disulfonic acid derivatives in the third stage, ie with a Cyanuric chloride derivative that only has one chlorine atom on each triazine ring. However, the yield of this procedure is only between 50 and 80% and therefore makes the procedure unattractive. There was therefore a need for exactly one C ₁ -C ₄ -alkoxy radical per cyanuric chloride unit in the bis-triazinylamino-stilbene-2,2'-disulfonic acids by a process by means of which one could selectively and with improved yields without the use of complex and expensive reagents can install.

According to US-A-3,951,965 bis-triazinylamino-stilbenedisulfonic acid derivatives described, each by stoichiometric implementation of the corresponding starting materials be preserved. However, such a procedure has disadvantages Product quality and yield.

A process has now been found for producing bis-alkoxy-triazinyl-amino-containing stilbene disulfonic acids or their derivatives, in which bis-chloro-triazinyl-amino-containing stilbene disulfonic acids are reacted with a C ₁ -C ₄ -monoalkanol, characterized in that that at least 10 moles of C ₁ -C ₄ -monoalkanol are used per 1 mole of bis-chloro-triazinyl-amino-containing stilbene-disulfonic acid or its derivatives and the C ₁ -C ₄ -monoalkanol is used together with water, the water content of the reaction mixture preferably 10-80% by weight, preferably 25-60% by weight, based on the reaction mixture.

In a preferred embodiment, at least 20 moles of the C ₁ -C ₄ -monoalkanol are used for 1 mole of a bis-chloro-triazinyl-amino-containing stilbene disulfonic acid or its derivatives. 50-500 moles, in particular 100-300 moles of C ₁ -C ₄ -monoalkanol per mole of the bis-chloro-triazinyl-amino-containing stilbene sulfonic acid compound are particularly preferably used.

The preferred C ₁ -C ₄ monoalkanols are methanol, ethanol, isopropanol, n-propanol, n-butanol, sec-butanol or tert-butanol, in particular methanol

The process for the preparation of 4,4'-bis [6-alkoxy-1,3,5-triazin-2-yl-amino] stilbene-2,2'-disulfonic acid is particularly preferred or their derivatives, their triazinyl residues are each substituted in the 4-position with amine residues.

The process according to the invention is preferably carried out in the presence of an acid-binding Carried out, preferably as the acid-binding agent Alkali hydroxide, especially potassium or sodium hydroxide is used. The Acid-binding agent is preferably used in an amount of 2 to 6 mol equivalents per mole of the bis-chloro-triazinyl-amino-containing stilbene disulfonic acid or its Derivatives used, preferably in an amount of 3 to 4 mol equivalents.

hergestellt, worin

M

für Wasserstoff, ein Alkalimetallion oder für ein gegebenenfalls substituiertes Ammoniumion steht,

R¹ und R²

unabhängig voneinander C₁-C₄-Alkyl bedeuten und

R³ und R⁴

unabhängig voneinander für einen Aminrest stehen.

The process according to the invention is generally carried out at temperatures from 0 ° C. to the boiling point of the reaction mixture, preferably at 15 ° to 80 ° C. In a preferred embodiment of the process according to the invention, compounds of the general formula (I)

manufactured in which

M

represents hydrogen, an alkali metal ion or an optionally substituted ammonium ion,

R ¹ and R ²

are independently C ₁ -C ₄ alkyl and

R ³ and R ⁴

independently represent an amine residue.

worin

R³, R⁴

und M die oben genannten Bedeutungen haben,

mit C₁-C₄-Monoalkanolen erhalten.The preferred compounds of the formula (I) prepared by the process according to the invention are obtained by reacting compounds of the formula (II)

wherein

R ³ , R ⁴

and M have the meanings given above,

obtained with C ₁ -C ₄ monoalkanols.

und in Summe von 2 Äquivalenten der Verbindungen R³H und R⁴H in beliebiger Reihenfolge erhalten.Compounds of the formula (II) are obtained, for example, by reacting 2 equivalents of cyanuric chloride with one equivalent of a compound of the formula (III)

and obtained in total of 2 equivalents of the compounds R ³ H and R ⁴ H in any order.

Preferred is the inventive method in which the compounds of Formula (II) can not be isolated between their preparation. Particularly preferred is the compound of formula (II) in the form of its aqueous reaction solution, if necessary after concentration and if necessary (partial) desalination to use in the manufacturing process according to the invention.

In a further preferred embodiment of the process according to the invention, the compounds of the formula (I) are obtained starting from a compound of the formula (II) in which R ³ and R ⁴ independently of one another are NR ⁵ R ⁶ , where R ^{5 is} hydrogen or optionally substituted C ₁ -C ₆ alkyl and R ^{6 can have} the meanings given under R ⁵ or optionally substituted C ₅ -C ₈ cycloalkyl or optionally substituted C ₆ -C ₁₀ aryl, or NR ⁵ R ⁶ for optionally by C ₁ -C ₄ alkyl, in particular methyl-substituted morpholino, piperidino or hexamethyleneimino

Preferred substituents of the C ₁ -C ₆ -alkyl radical in the meaning of R ⁵ and R ⁶ are, for example, hydroxyl, C ₁ -C ₆ -alkoxy, C ₂ -C ₈ -alkoxy-substituted C ₂ -C ₈ -alkoxy, C ₁ -C ₆ alkylamino or C ₁ -C ₆ dialkylamino, cyano or sulfonic acid or sulfonate.

Preferred substituents for C ₅ -C ₈ cycloalkyl are: halogen, in particular fluorine, chlorine and bromine, C ₁ -C ₆ alkyl, C ₁ -C ₆ alkoxy, sulfamoyl or sulfonyl, in particular C ₁ -C ₄ - Alkyl.

Sulfo-substituted phenyl is particularly suitable as an optionally substituted C ₆ -C ₁₀ aryl.

R ⁵ very particularly preferably represents hydrogen, methyl, sulfoethyl or its alkali salt or hydroxyethyl and R ^{6 represents} sulfoethyl or its alkali salt, hydroxyethyl or disulfo-substituted phenyl.

In a particularly preferred embodiment, the radicals R ³ , R ⁴ and R ¹ and R ^{2 are} identical.

The radical M which is preferably hydrogen or an alkali metal such as sodium, Potassium or lithium does not have to be on every sulfonic acid group in the molecule be identical.

It is further preferred to adjust the reaction mixture obtainable by the process according to the invention to a pH of less than 10, preferably less than 8, and to remove the excess C ₁ -C ₄ -monoalkanol, preferably by distillation.

worin

M

die oben angegebene Bedeutung besitzt.

The invention further relates to compounds of the formula (I) which correspond to the formula (IV)

wherein

M

has the meaning given above.

Preferred compounds of the formula (IV) are those in which the SO ₃ M groups of the terminal benzene ring are in the 2- and 5-positions.

The compounds of formula (IV) can be analogous to the procedure described above getting produced.

The compounds (I) prepared by the process according to the invention and the new compounds of the formula (IV) are outstandingly suitable as optical brighteners for organic materials, preferably for cellulose, polyamide, wool, silk and Paper, in particular for photographic paper. They can also be added to detergents. The compounds of formula (I) can e.g. incorporated in bulk or on the Surface of the materials to be lightened are applied. Particularly preferred The amounts used are 0.0001 to 2% by weight, based on the material to be lightened.

The percentages given in the examples below are each Percentages by weight.

example 1

1,000 g of methanol, which contains 10% water, are presented. Then be 185 g sodium hydroxide solution 10% added. The temperature is set to 35 ° C. Then a solution of 167 g of 4,4'-bis [(4- (2,5-disulfo) anilino-6-chloro-1,3,5-triazine) solution of 167 g of 4,4'-bis [1 2-yl) amino] -stilbene-2,2'-disulfonic acid hexasodium salt dropped in 1275 ml of water. The temperature is kept for 2 hours.

The pH is adjusted to 6.5 to 7.0 in about 1 hour by adding 10% hydrochloric acid. Then methanol or methanol-water is distilled off until a constant boiling point of 100 ° C. is reached. The mixture is made up to 1500ml with water at approx. 30 ° C.
The solution is then suctioned off first through a blue-band filter and then through a 0.8 μm filter in order to free the solution from all turbidity and suspended matter which impede the permeate flow. The 1500 ml are filled into a pressure permeation system. The first 500 ml of permeate are removed at 40 to 50 ° C and approx. 40 bar. 500 ml of water are added and the second approx. 500 ml of permeate are removed. 500 ml of water are added and the third approximately 500 ml of permeate are removed. 500 ml of water are added and the fourth approximately 500 ml of permeate are removed. The concentrate is evaporated to dryness in a crystallizing dish in a vacuum drying cabinet (50 ° C.) and comminuted in a friction dish.

Yield: 160 g of yellow powder 4,4'-bis [(4- (2,5-disulfo) anilino-6-methoxy-1,3,5-triazin-2-yl) amino] -stilbene-2,2 ' -disulfonic acid hexasodium salt.

The product contains less than 2% NaCl and approx. 1% H ₂ O, so that the theoretical yield is approx. 94%.

Example 2

1,000 g of methanol, which contains 5% water, are presented. Then be 185 g sodium hydroxide solution 10% added. The temperature is set to 40 ° C. Then 1,200 ml of an aqueous solution are introduced at 40 ° C. within 1 hour, the approx. 65 g of 4 - [(4-diethanolamino-6-chloro-1,3,5-triazin-2-yl) amino) 4 '- [(4-sulfoethylamino-6-chloro-1,3,5- triazin-2-yl) amino] stilbene-2,2'-disulfonic acid trisodium salt, 15 g of 4,4'-bis [(4-diethanolamino-6-chloro-1,3,5-triazin-2-yl) amino] stilbene-2,2'-disulfonic acid disodium salt and 65 g of 4,4'-bis [(4-sulfoethylamino-6-chloro-1,3,5-triazin-2-yl) amino] stilbene-2,2'-disulfonic acid tetrasodium salt contains. The temperature is kept for 2 hours.

The pH is adjusted to 6.5 to 7.0 in about 1 hour by adding 10% hydrochloric acid. Then methanol or methanol-water is distilled off until a constant boiling point of 100 ° C. is reached. is. The mixture is made up to 1,800 ml with water at approx. 40 to 50 ° C. The solution is then suctioned off first through a blue band filter and then through a 0.8 μm filter in order to remove all turbidity and suspended matter which impede the permeate flow to free. The 1,800 ml are filled in a pressure permeation system at 40 to 50 ° C and approx. 40 bar, the first 600 ml permeate are removed. 600 ml of water are added and the second approximately 600 ml of permeate are removed. 600 ml of water are added and the third approximately 600 ml of permeate are removed. 600 ml of water are added and the fourth approximately 600 ml of permeate are removed. The concentrate is evaporated to dryness in a crystallizing dish in a vacuum drying cabinet (50 ° C.) and comminuted in a friction dish.
Yield: 140 g of light yellow powder.

The product contains less than 1% NaCl and less than 1% water, so that the theoretical yield is 95%

Example 3

1,000 g of methanol, which contains 5% water, are presented. Then be 185 g sodium hydroxide solution 10% added. The temperature is set to 45 ° C. Then 600 ml of aqueous 45 ° C. warm solution are introduced at 45 ° C. within 1 hour, the approx. 65 g of 4 - [(4-diethanolamino-6-chloro-1,3,5-triazin-2-yl) amino] -4 '- [(4-sulfoethylamino-6-chloro-1,3,5 -triazin-2-yl) amino] stilbene-2,2'-disulfonic acid trisodium salt, 15 g of 4,4'-bis [(4-diethanolamino-6-chloro-1,3,5-triazin-2-yl) amino] stilbene-2,2'-disulfonic acid disodium salt and 65 g of 4,4'-bis [(4-sulfoethylamino-6-chloro-1,3,5-triazin-2-yl) amino] stilbene-2,2'-disulfonic acid tetrasodium salt contains. The temperature is kept for 2 hours.

The pH is adjusted to 6.5 to 7.0 in about 1 hour by adding 10% hydrochloric acid. Then methanol or methanol-water is distilled off until a constant boiling point of 100 ° C. is reached. The batch is made up to 1200 ml with water at approx. 50 ° C. The solution is then suctioned off first through a blue-band filter and then through a 0.8 μm filter in order to free the solution from all turbidity and suspended matter which impede the permeate flow. The 1,200 ml are filled into a pressure permeation system. The first 400 ml of permeate are removed at approx. 50 ° C and approx. 40 bar. 400 ml of water are added and the second approximately 400 ml of permeate are removed. 400 ml of water are added and the third approximately 400 ml of permeate are removed. 400 ml of water are added and the fourth approximately 400 ml of permeate are removed. The concentrate is evaporated to dryness in a crystallizing dish in a vacuum drying cabinet (50 ° C.) and comminuted in a friction dish.
Yield: 140 g of yellow powder.

The product contains less than 1% NaCl and less than 1% water, so that the theoretical yield is 95%.

Example 4

1,000 g of ethanol, which contains 10% of water, are initially introduced 185 g sodium hydroxide solution 10% added. The temperature is set to 45 ° C A solution of 167 g of 4,4'-bis [(4- (2,5-disulfo) anilino-6-chloro-1,3,5-triazine) at about 45 ° C. is then heated at 45 ° C. within 1 hour. 2-yl) amino] -stilbene-2,2'-disulfonic acid hexasodium salt dropped in 1 275 ml of water. The temperature is kept for 4 hours.

The pH is adjusted to 6.5 to 7.0 in about 1 hour by adding 10% hydrochloric acid. Thereafter, ethanol or ethanol-water is distilled off until a constant boiling point of 100 ° C. is reached. The mixture is made up to 1500 ml with water at approx. 50 ° C
The solution is then suctioned off first through a blue-band filter and then through a 0.8 μm filter in order to free the solution from all turbidity and suspended matter which impede the permeate flow. The 1,500 ml are filled into a pressure permeation system. The first 500 ml of permeate are removed at 40 to 50 ° C and approx. 40 bar. 500 ml of water are added and the second approx. 500 ml of permeate are removed. 500 ml of water are added and the third approximately 500 ml of permeate are removed. 500 ml of water are added and the fourth approximately 500 ml of permeate are removed.
The concentrate is evaporated to dryness in a crystallizing dish in a vacuum drying cabinet (50 ° C.) and comminuted in a friction dish.
Yield: 165 g of yellow powder 4,4'-bis [(4- (2,5 disulfo) anilino-6-ethoxy-1,3,5-triazin-2-yl) amino] -stilbene-2,2'-disulfonic acid hexasodium salt .

The product contains less than 2% NaCl and less than 2% water, so that the theoretical yield is 93%.

Example 5

425 g of methanol and 75 ml of water are presented. Then 18 g 45% sodium hydroxide solution are added. Then 83 g of 4,4'-bis (2-anilino-6-chloro-1,3,5-triazin-2-yl) amino] -stilbene-2,2'-disulfonic acid disodium salt with a water content of 40% are added. One heats up to the RF. After 1 h of RF, 10 ml of saturated sodium chloride solution are added at about 70 ° C., the mixture is brought to RT, filtered off with suction, washed with 160 g of methanol and dried at 50 ° C. in vacuo.
Yield: 49 g of yellow product 4,4'-bis (2-anilino-6-methoxy-1,3,5-triazin-2-yl) amino] -stilbene-2,2'-disulfonic acid disodium salt, corresponding to 99. 5% of theory.

Example 6

800 g of methanol and 350 ml of water are presented. Then 81 g of 10% sodium hydroxide solution are added. Then 100 g of 4,4'-bis [(2- (4-sulfo) anilino-6-chloro-1,3,5-triazin-2-yl) amino] -stilbene-2,2'-disulfonic acid tetrasodium salt registered with a water content of 40%. The mixture is heated to 60 ° C. and kept at 60 ° C. for 1 hour.
The pH is then adjusted to 6.5 to 7.0 in about 1 hour by adding 10% hydrochloric acid. Then methanol or methanol-water is distilled off until a constant boiling point of 100 ° C. is reached. The mixture is made up to 500 ml with water at approx. 50 ° C. and adjusted to pH 9.0 with 10% sodium hydroxide solution.

The solution is then suctioned off first through a blue-band filter and then through a 0.8 μm filter in order to free the solution from all turbidity and suspended matter which impede the permeate flow.
The 500ml are filled in a pressure permeation system. The first 150 ml of permeate are removed at 40 - 50 ° C and approx. 40 bar. 150 ml of water are added and the second approximately 150 ml of permeate are removed. 150 ml of water are added and the third approximately 150 ml of permeate are removed. 150 ml of water are added and the fourth approximately 150 ml of permeate are removed. The concentrate is evaporated to dryness in a crystallizing dish in a vacuum drying cabinet (50 ° C.) and comminuted in a friction dish.
Yield: 56 g of yellow powder 4,4'-bis [(2- (4-sulfo) anilino-6-methoxy-1,3,5-triazin-2-yl) amino] -stilbene-2,2'-disulfonic acid tetrasodium salt

The product still contains 1% NaCl and 2% water, so that there is a yield the theory of 92%.

Claims (9)

1. Process for the preparation of stilbene-disulphonic acids containing bis-alkoxytriazinyl-amino, or derivatives thereof, characterized in that a stilbene-disulphonic acid containing bis-chloro-triazinyl-amino, or a derivative thereof, is reacted with a C₁-C₄-monoalkanol, at least 10 mol of C₁-C₄-monoalkanol being employed per mol of the stilbene-sulphonic acid containing bis-chloro-triazinyl-amino, or derivatives thereof, and the C₁-C₄-monoalkanol being employed together with water, the water content of the reaction mixture being 10-18% by weight, based on the reaction mixture.
2. Process according to Claim 1, characterized in that at least 20 mol of C₁-C₄-monoalkanol are employed per mol of the stilbene-sulphonic acid containing bis-chloro-triazinyl-amino, or derivatives thereof.
3. Process according to Claim 1, characterized in that methanol is used as the C₁-C₄-monoalkanol.
4. Process according to Claim 1, characterized in that the reaction is carried out in the presence of an acid-binding agent, in particular an alkali metal hydroxide.
5. Process according to Claim 1, characterized in that the stilbene-disulphonic acid containing bis-alkoxy-triazinyl-amino corresponds to the formula (I)

   

   wherein

   M

   represents hydrogen, an alkali metal ion or an optionally substituted ammonium ion,

   R¹ and R²

   independently of one another represent C₁-C₄-alkyl and

   R³ and R⁴

   independently of one another represent an amine radical,

   and is prepared starting from compounds of the formula (II)

   

   wherein R³, R⁴ and M have the abovementioned meaning.
6. Compounds of the formula (IV)

   

   wherein

   M

   represents hydrogen, an alkali metal or optionally substituted ammonium.

7. Compounds according to Claim 6, characterized in that the two SO₃M groups of the terminal benzoring in the formula (IV) are in each case in the 2- and 5-position.
8. Use of stilbene-disulphonic acids containing bis-alkoxy-triazinyl-amino, or derivatives thereof, according to Claim 6 or 7, for optical brightening of organic materials, in particular of cellulose and paper.
9. Organic material, in particular cellulose or paper, comprising 0.0001 to 2% by weight of a compound according to Claim 6.